Translation:Do you want brown or white sugar in your tea?
Good question, I'd also have used dative here, but accusative is not wrong if you understand it as a "motion", like "do you want me to put brown or white sugar in(to) your tea".
Pish posh! Cricket is such a tinny word. Gorn...now that's a woody word.
There is no brown sugar in Germany. They simply do not know what is brown sugar. I tried in many hotels in Germany (Munich to Stuttgart) to have brown sugar with my coffee but I could not get it. They would stare at me: What do you mean? What are you talking about?
just in case you want to improve your English: the correct word order would be "what brown sugar is"
it is the strong declension in accusative case. i.e. möchten takes accusative for the direct objects after it, and since there's no article, then "braun" has to convey the gender/number/case info
No, "Do you want brown or white sugar into your tea?" is not correct in English, but you could say "Do you want to put brown or white sugar into your tea?" However I think that's not really a direct translation of the German sentence.